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 Signature Internal Medicine

Concierge Internal Medicine located in Frisco, TX

Dr. Ahmed and Dr. Diehl
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What is concierge medicine?

Signature Internal Medicine is a superior concierge internal medicine practice in Frisco, Texas, led by Humera Ahmed, MD, and Dina Diehl, DO. The skilled providers offer comprehensive primary care services for men and women 18 and older.

Signature Internal Medicine offers 24/7 access to physicians any time patients need them. Providers spend as much time as patients desire to ensure exceptional care, so appointments never feel rushed.


  • 24/7 access to your physician by phone, email, text
  • 30-60+ minute appointment times 
  • Little or no office wait times
  • Complimentary health coaching
  • Comfortable, relaxing environment
  • Comfortable, friendly environment
  • Improved disease management
  • Early disease detection with advanced testing options
  • Cutting-edge diagnostics and treatments offered
  • Same-day or next-day appointment availability
  • Personalized attention to your needs
  • Specialist referrals in timely fashion 
  • Coordination of follow-up care
  • White glove service

Annual membership fee : individual $3000/year, couples $5000/year.  This fee can be paid annually, biannually or quarterly. This fee is not covered by insurance. Our annual membership covers these practice benefits. We accept most insurances for medical visits, labs, and diagnostic testing if applicable. You may request a complimentary meeting with one of our providers to see if they are right for you.

Well-trained, experienced physicians at Signature Internal Medicine specialize in preventive health care. The offer executive level annual physicals with option for extensive lab testing, imaging in addition to comprehensive internal medicine services, and more.
Optional add on labs:
  • Advanced Cleveland Heart Labs
  • Extensive Thyroid panel
  • Hormone analysis (i.e Dutch testing) 
  • Gut microbiome analysis ( GI MAP test)
  • Food Sensitivity Testing 
  • Adrenal/Cortisol Analysis 
  • Detailed Vitamin Analysis 
  • Metabolism/Amino Acid Testing 
  • Neurotransmitter Testing
  • Toxin Evaluation 
  • Oxidative Stress Analysis 

The practice provides exceptional concierge medicine, which is a newer approach to healthcare in which your primary care physician limits the size of the practice. This allows them to spend more time with patients and deliver the personalized attention they deserve.

Along with 24/7 access to your provider, concierge medicine provides same-day or next-day appointments with little to no office wait times. Your Signature Internal Medicine provider focuses on patients’ unique needs, tailoring treatment plans just for them.

The highly-trained providers care for patients with diabetes, chronic obstructive pulmonary disease (COPD), high cholesterol, hypertension, osteoporosis, gastrointestinal reflux disease (GERD), and mental health conditions. 

Signature Internal Medicine offers medical weight loss, chronic disease, and acute illness management, prescription medicines, cancer screening, smoking cessation, on-site diagnostic testing, and much more. The internal medicine providers work and communicate closely with specialists, referring patients to them when necessary.

The Signature Internal Medicine specialists warmly welcome their patients to the practice and look forward to caring for them. 

Call the office or use the online booking tool today to schedule an appointment at Signature Internal Medicine.

Meet Our Providers

Dr. Diehl and Dr. Ahmed currently have privileges at Texas Health Hospital Plano & Texas Health Hospital Frisco
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Dr. Diehl

- American College of Physicians
- Certified Functional Medicine Provider
-Member of Institute of Functional Medicine
-Member of Obesity Medicine Association
-Member American Medical Association
- National Committee for Quality Assurance Excellence in Diabetes Care 2017
- Board member at Texas Health Presbyterian, 2010 
- Certificate of Recognition for Delivery of Quality Cardiovascular and Stroke Care 2017-2020

- America's Most Honored Professionals 2019 - Top 5%
- America's Most Honored Professionals 2018 - Top 1%
- America's Most Honored Professionals 2017 - Top 5%
- Compassionate Doctor 2015
- Compassionate Doctor 2016
- On-Time Physician Award - 2016
- On-Time Physician Award - 2015
- Patients' Choice 2016
- Patients' Choice 2018

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Dr. Ahmed

- D-Magazine Best Internist in 2018 and 2019
- Member of Institute of Functional Medicine 
- National Committee for Quality Assurance Excellence in Diabetes Care, 2017
- Recognized for Delivery of Quality Cardiovascular and Stroke Care, 2017-2020
- Board member at Texas Health Presbyterian, 2010
- Member of the American College of Physicians
- Member of Obesity Association
- Top doctors of America selected in 2022
- America's Most Honored Doctors - Top 5% 2022
- America's Most Honored Doctors - Top 5% 2021
- America's Most Honored Doctors 2020 - Top 5%
- Compassionate Doctor 2020
- On-Time Physician Award - 2020
- Patients' Choice 2020
- Patients' Choice 2019
- Biote Certified
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Patient Reviews

I was able to speak with Sr. Ahmed, ask questions and get answers without feeling rushed. She was very knowledgeable, attentive and made me feel very comfortable. Highly recommend.

Genie P. | Mar 22, 2023
For the first time I felt heard and listened to. Dr Diehl is simply amazing and treats the whole person not just symptoms. It is worth it!

Tammye G. | Feb 28, 2023
Dr Ahmed was caring, explained the problem & the rx.

Lila A. | Feb 12, 2023
Dr Ahmed and staff are top notch. Friendly, great communication, thorough, accessible, knowledgeable, and truly an excellent practice. I could not be more pleased.

Edward R. | Feb 03, 2023
Very Relaxing not rushed get one on one focus. Professional Love It !

Jannie C. | Dec 13, 2022
Wonderful doctor!

Mary S. | Nov 22, 2022
The facility and the service is state of the art.. from the time you walk in you feel you are in an environment where you automatically you feel relax unlike other clinics super friendly and welcoming staff.. amazing care and love love the energy . Care I received was above and beyond .. amazing, Dr Ahmed is polite kind knowledgeable and professional.. love her energy as positivity..

Saira H. | Nov 20, 2022
Very thorough, knowledgeable, kind and helpful so glad I changed doctors

Debra D. | Nov 11, 2022
Love the personal, confident approach to medical care that Dr Diehl provides. She listens, finds the best solutions, and offers quality follow up. A great experience.

Gregory M. | Oct 18, 2022


We accept most insurance providers. If you have specific questions regarding your coverage, please contact us for additional information.

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